Hi & welcome, Vbx! Agree, the mental boost even if only from a placebo effect of the belief that the atmosphere is improved in some way by the addition of plants does have value. Any inherent value may be debatable and difficult to quantify but the mental aspect is worthy of attention, as far as my opinion goes. I believe there are people who notice and appreciate plants more than others, and if so, the effect would not be universal for all people but very effective for those who are affected.
